An injection device as defined above is known e.g. from EP 1 974 761 B1 wherein the nut is keyed to an outer main housing and may be advanced along a thread on a drive sleeve. When a final dose dispensed position is reached, a radial stop formed on a surface of the nut abuts a radial stop on a surface of the drive sleeve, preventing both the nut and the drive sleeve from rotating further.
In addition, a drive mechanism including a torsion spring is known from EP 1 909 870 B1. This device comprises a limiter which is coupled to a driver and a piston rod such that relative rotation between the driver and the piston rod during dose setting causes the limiter to move towards a stopping position wherein the limiter prevents setting of a dose which exceeds the amount of a medicament in a reservoir in the injection device. As the piston rod has a small diameter compared with the driver and the torsion spring, limiting actuation of the device and thus withstanding a relatively high torque via the piston rod may be difficult in some cases.
As a further alternative, EP 1 570 876 B1 suggests a limiting mechanism for an injection device which prevents the setting of a dose exceeding the amount of liquid left in a cartridge of the injection device. The mechanism comprises a nut member and a cylindrical driver provided with a helical thread at its outer surface, the helical thread having an end defining a threadlength which is related to the total amount of medicine in the cartridge. The nut member is provided with a thread engaging said helical thread of the driver. This mechanism requires that a dose setting member is screwed outward in a housing when rotated to set a dose and it is pressed into said housing when the dose is injected or when rotated to reduce a too large set dose. In some cases, this requirement may be considered as a drawback.
WO 2008/031235 A1, WO 2009/070911 A1 and WO 2009/105909 A1 disclose mechanisms with a nut located between a driver and a dial member. The dial member is moved axially for dose dispensing. In addition, WO 2012/125876 A1 discloses a mechanism with a nut located between a driver and a dial member with the driver moving axially during dose setting and/or dose resetting.